Impact drill



J. A. vZUBLIN IMPACT DRILL June 1 1926.

Filed August s, 1922 2 sheets-'sheet 1 J. A. ZUBLIN IMPACT DRILL June 1 1926.

Filed August 9, 1922 2 Sheets-Sheet 2 an impact drill having a depending y Patented June 1, 1926.

A UNITED STATES JonN A. zUBLIN, or Los ANGELES, CALIFORNIA.

:IMPACT DRILL.

Application mea August s, ma. semi No. 580,045.

' drilling is accomplished by the blade'which breaks or splitsthe material fromthe bottom of the well bore, the reaming"4 cutters functioning to producel a round straight hole.

Another object is to provide a drill ofthe above character in which the under surfaces of the shoulders act as impact surfaces serv- 7 ing to crush the loosened material and mix soft material with circulation water 1n' the well bore.

A. further object resides in theangling ot the under surfaces of the shoulders upwardly from the base of the bladewhereby-by reason of the disposition of the shoulders onopposite' sidesof the vertical axis of the drill combined with their being angled iny opposite directions, the action of\ said shoulders against the circulation water and a ainst the earth will eliect a partial rotation o the drill during each downward stroke so that the cutter` blade will strike the bottom of' the hole at substantially regular circular intervals, this action contributing to the production of a straight round bore.

Another object is Ito provide an impact,` ydrill having a dependingv transverse cutter blade and two diagonally opposite side wings o1" shoulders on opposite sides of said blade dressed out to form concentric reaming cutL ters, whereby the'blade penetrates the formation without shattering the surrounding 'part of the ground thereby avoiding caving of the walls in unconsolidated formations, the reaming `cutters subsequently reaming the bore tofull diameter.

A further object 1s to providea drill as above referred to in which the blade breaks or loosens thel material from the bottom of the bore, and in which the shoulders are dressed backwards'and upwards in a manner similar to propeller win s and function to crush the material an to force the loosened material away from the shoulders, i

partly into flutes in the drill shank, and

trans.-

` partly into the walls@ of the bore when-working 1n soft or unconsolidated formation.

Various other objectsv and advanta es be more. fully apparent vfrom the ollowmg descr tion of the accompanying drawlngs, which form a part Vof this disclosure, and which illustrate a preferred form of embodiment of the'invention. v

Of the drawings:

' Figure 1 is an elevation of my improved tyeof drill.

1g. 2 is aplan section on line 2 2 of Fig. 1.

Fig. 3 is a bottom plan view. Fig. 4 is an elevatlon of the lower portion .Figj is asimilar elevation looking in the direction of the arrow 5 in Fig. 2.

Fig. ,6 is a perspective view'or'I asection of d rill stock from which the drill is formed. Fig. 7 1s a Yperspective view illustrating the iirst step in the formation of the drill.

' Fig. 8 is a perspective view of the lower end of the completed drill.

of the drill; shown in a well bore and look- I ing 1n the direction of the'arrow 4in Fig. 2.`

9 is a bottom plan yview of a iece of Fi stanarddrill stock illustrating the rst step in the formation of my. improved drill from such stock.

Fig. 10 is a view similarv to Fig. 1, illustrating a slight modification of the form of the transverse cutter blade.'

Fig. 11 is an elevation of a standard typeof bevel bit or drill,in'a well bore.`

Fig. 12 is -an elevation of a standard type 4of flat bottom bit or drill, in a well-bore.

' Fig; 13 is a diagrammatic illustration of `.thepacking eli'ect of a standard flat bottom bit. ,In the now in general use, two standard types of drills or bits are generally employed, namely, a beveled bit as shown in Fig. 11 and having its lower end dressed to form two inclined transverse planes 1 forming a central cutting edge 2, and a flat bottom bit as shown in Fig. 12 and in which the cutting and rcaming edges 3 areof the full diameter vof the well bore.

The beveled bit shown in Fig. 11 has no crushing planes by which the boulders or larger pieces of hard material will be crushed and such material, indicated at a, contacting with one or the other of the .beveledsurfaces 1 will tend to' deflect the drill sidewise, as indicated by the arrow b, with as well known cable drilling system I the result that a crooked bore will be produced. Further, as such a drill has no rotary movement excepting such as can be eiected from the surface by manipulation of the drill cable, it often happens that the drill will key-seat in the well bore, that is, by striking the same spot at each downward Stroke the drill will form ahole of the exact shape of the drill instead of forming a round hole and after a few strokes will become stuck in the formation.

With a flat bottom bit of the form show in Fig. 12, and working in unconsolidated formation, the fiat bottomcompresses and packs the formation in the area 4 rendering it more diilicult to break up, and further by continual pounding against such packed for.

mation, tends to shatter the surrounding formation making it more liable to cave into the hole and-bury the whole string of tools. This action produces a bore having a hard packed bottom and relatively loose side Walls, as diagrammatically illustrated in Fig. 13 which is the reverse of an ideal condition of soft bottom which the drill has to break up and hard sides to prevent caving. The entire work of cutting and reamin is accomplished entirely by the cutting e ges 3 which must break the material in a corner in which one-quarter or 90 of the circle is open and three-quarters or 270 of the circle is of solid material, as indicated in Fig. 12, this condition requiring that the bit has to break the material at a point ol'ering the greatest resistance. Thus, the entire drillin strains are localizedat the two cutting e ges with the result that such a bit rapidly wears to such an extent as to require. frequent removal for redressing and resharpemng.

Summing up the deficiencies and objectional features incident to the use of such standard drilling tools, the beveled bit of Fig. 11 is very susceptible of being laterally deflected and cannot be relied upon to Vbore a straight hole, and further is very susce tible of becoming key-seated in the well ore. The flat bottom bit of Fig. 12, by first packing the formation which it must subsequently break up, creates a condition adding to the work which the'drill must perform, and also creates a conditionvr by reason of which the bore, in loose formations, is very liable to cave in. Even under favorable conditions the drill speed of the dat bottom bit is relativel low, andwhile the drilling speed` of the eveled bit is considerably greater, its tendency to bore crooked holes quite offsets any advantage in actual drilling speed. While the flat bottom bit causes a very effective mixingof the loosened material with the water, due to the vacuum influence created beneath the large ilatsut face during the up-stroke and the abrupt displacement of water by said flat surface on the down stroke, neither of said standard bits positively direct the material up into the flutes, and for this reason only such material as happens to find its Way into the iluteswill be carried up the drill shank by the water.

With the above in mind I have invented a new type of impact drill which while retaining the mixing effect of the flat bottom bit, has nonel ofv the above named objectionable features, and which by actual field tests show an increase of drilling speed vof not less than one hundred percent.

The drill of the present invention may be formed from the standard type `of drill stock shown in Fi 9, or from drill stock of the shape shown 1n Fig. 6, the only difference belng that the special type of drill stock eliminates corners and edges which are unnecessary and which complicate slightlloy. the Work of forming and dressing the In Fig'. 6, I have illustrated the preferred type of drill stock from which my lmproved drill is preferably formed, and which has opposite vertical edge surfaces 5, adjacent angled corner surfaces 6, and opposed longitudinal flutes 7, with the walls of the flutes angled outwardly to meet the edges of the corner surfaces 6.

In the drill as shown in Fig; 1, the upper portion of the shank 8 is formed to provide the usual type of neck 9`having flat surfaces 10 for engagement by suitable wrenches or other tools, and a screw-threaded tapered pin 11 adapting the tool for attachment to the tool strin v A preferre manner of forming the drill from the type of drill stockshown in Fig. 6, consists of first cutting back the stock along dotted lines 12 connecting two of the opposed corner surfaces 6, down to the dot- IOil ted'lines 13, preferably by means of an acetylene torch, thus forming a diagonal central web 14 and diagonally opposite shoulders .1-5 on o posite sides of said web, as shownin Fig. l

With the drill stock cut back in this manner, the'drillis forged or otherwise formed to thev shape shown in-Fig. 8, the web 14 being dressed to form a transverse cutting blade 16 extending downwardly from the shank 8 between the flutes 7 and diagonally disposed relative to the disposition of the flutes with the sides of the blade tapered and beveled to a chisel cutting edge.

The res ective shoulders 15 are an led upwardly e rom the base of the cutting b ade 16 to their outer points 17, and are dressed out to circular cutting edges 18 coincident to the fulldiameter of the well bore, these shoulders functioning as impact shoulders to crush the loosened material and as reaming cutters for reaming the well bore to size. f

With the impact surfaces angled -upwardly andl outwardly from the base of the blade 16 to the points 17, the cutting edges 18 will be langled circularly from their forward points 20 backwardl to thel respective rearwar drill and are angled in opposite directions from the blade 16, it will be understood that upon each down-stroke, the shoulders will have ascrew-like` action u'pon the circulation water and upon the formation during reaming, efecting'a partial rotation of the drill ners 22 which will be dressed back, `or which in the direction of the arrows 21in the several views.'

In some instances it may be desirable to form 'the cutting blade of suiicient width to span the entire diameter of the well bore, .whereby the blade does substantially all the Work of boring. excepting for the work of truing the bore which is accomplished by` the reaming cutters. In such instances the blade 16 -may be'dressed outwardly to the full diameter as shown in Fig. 10.

In .forming a drill 'from standard drill stock of the shape shown in Fig. 9, the web 14 may be disposed. asshown, leaving cormay '.be left without such dressingl back as vin ' operation of the drill.

material cut by the. blade, forcing such cuttings into the-.flutes 7, as indicated by the arrows 23, and in loose or' unconsolidated formation partly back into the wall of the bore, as indicated the arrows 24, thereby reinforcing and packing such Wall to reduce danger of:` caving thereof. This crushing action does not packthe material at the bottom of the bore, as do lthe standard types of bits, for the reason that this crushing action centers at oints 25 which arel outwardly from the si e walls of the bore, as illustrated in Fig'. 5.

Vixen the reaming shoulders strike the formation in a. reaming o ration a positive rotation of the drill is e yected by reason of 4 said shoulders being respectively on opposite sides of the vertical axis of the drilland by reason of their being respectively angled 11p- Wardly and circumferentially in opposite directlons inthe form of a screw-thread.

and upwardly y points 17,-the terms forward and rearwardv as used being ,coincident to the, directions of rotation'of the drill, and' as the respective shoulders. are on opposite-sides of the vertical axis'of the they will have no appreciable effect on'the `The work of redressing the'drill consists length, sharpening said blade, and redressing the reamingedges of the shoulders to size. This can be accomplished in the field or in. 'a shop, as desired.

In ,the actual operation of my bit, the cutting blade -16 is of suicient length toenter the`- material at 'the bottom of thel hole and to penetrate therein before the impact shoulders 15 strike this material. As a result, the bit has a doublecutting action. The cutting blade enters the formationwithout rotation and. after it has penetrated sufiiciently t-o bring the impact shoulders into contact with' the material at the bottom of the hole, it is given a' marked twist. This twist is due the same direction as they wedge against the b ottom'of'the hole and because their maximum action` is exerted at the greatest possipile1 radius, that is, at the periphery of the o e. e This double cutting vaction is most important as the cleavage planes of the formations ordinarily penetrated are roughly horizon--` tal, orat a sm'all angle with the horizontal. The twisting action, therefore, ten-ds to shear oi viakesiof material along thesel cleavage planes and', since the materials drilled have, ordinarily, very little shearage strength along these planes, twisting action is most effective.

To be effective, however, the bit must be made, as shown, in such a manner that the cutting blade penetrates the material, with'- out twisting, sufficiently to get a twisting grip on the material before impact shoulders' strike bottom and supply the twist.

My bit cuts, as do all impact bits, by virtue of the energy stored therein at the moment of impact. A portion of this energy is aplied --to forcing the cutting blade into the ormation to be cut, a portion is applied to reaming the hole by the impact-shoulders,` and a portion isconverted into lrotary motion for the purpose l of turning the cutting blade and thereby shearing off material from the bottom of the hole'.

SoL-faii as I am now aware, I am the iirst to, fovide a bit witha'cutting blade which is nrs't" driven into the material to be .drilled and then twisted to shear olf flakesfof this material. I am also the first to cause a freely suspended and reciprocated bit to cut both by impactand rotation, using the stored energy in the moving bit for both pur oses.

While the drill as illustrated and escribed hereinl is Well adapted to fulfill the objects primarily stated, it is to. he understood that I do not wish to limit the invention to the embodiment herein disclosed, kfor itis susceptible of embodiment in various other following claims.

I claim:

1. An impact drill adapted to rotate during its impact stroke and having a shank provided with flutes on opposite sides thereof and a transverse cutting blade between the flutes and extending downwardly from the shank, the lower surface of the shank forming opposed impact surfaces on opposite `sides of the blade and the blade being diagonally disposed relative to the disposition of the flutes so that approximately the entire area of each impact surface is positioned to one side of th-e adjacent flute, each impact surface being extended rearwardly relative to the direction of rotation and angled upwardly from the base of the blade.

2. An lmpact drill adapted to rotate during its impact stroke and having a -shank and a transverse cutter blade extending downwardly therefrom,` the shank at the base of the bladeV having two diagonally opposite side wings or shoulders on opposite sides of the blade to provide impact crushing surfaces angled upwardly from the base of the bla-de with the outer edges of the shoulders being dressed out concentric to the vertical axis of the shank to form rea1n ing cutters.

3. An impact drill adapted-to rotate during its impact stroke and having a shank and a transverse cutter blade extending downwardly therefrom, the shank havingtwo diagonally, opposite side wings or shoulders extending rearwardl relative to the directionof rotation and isposed on opposite sides of the blade to provide crushing A impact surfaces 4angled upwardly from the base of said blade with their outer edges angled upwardlyand circumferentially and dressed out concentric to the vertical axis of the shank to form reaming cutters.

4. An impact drill including a shank provided with a 4relatively thin cutter blade having` a transverse cutting edge andopposite side walls, the loweriend of the shank havin two diametrically o posite impact shoul ers on opposite sides o the blade and diagonally disposed relative to the plane of the blade, each shoulder extending outwardgroin the base of the side wall of the a e.

operating by falling through a distance in a well andcomprising: a cutting blade having sides forming equal angles with the cen- A tral plane of the blade; and impact'shoulders situated on opposite sides of said plane and on opposite sides of a plane at right angles thereto and passing through the axis of said bit, said impact shoulders being so li)nclined that they cooperate to rotateV the 6. A bit for drilling dee wells, Said bit operating by falling tlirougih a`distance in a well and .com rising: a cutting blade adapted to be driven into the material to be cut Without rotation and so formed as to exert a twisting grip on said material when so driven; impact shoulders yformed on said bit, said impact shoulders being situated on opposite sides" of said cutting blade and so s aped and situated as to impart a twisting moment to said bit as they are forced into vsaid material; and cutting edges formed at the outer parts of lsaid impact shoulders.

7. A bit for drilling deep wells, said bit v operating by falling through a distance in a well and comprising: a cuttingblade adapted to 'be driven into the material to be cut without rotation'and so formed as to exert 5. A bit for deuingdeep wens, Said bit a twisting grip on said material when so driven; impact shoulders formed on said bit, said 'impact shoulders being situated on opposite sides vof said Acutting blade and so shaped and situated as toA impart a twisting moment to said bit as they are forced into JOHN A azUBLIN.' 

